Propeller reversible blade and wood-retaining ferrule



1922 2 Sheets-Sheet 1 E. G. M CAULEY PROPELLER REVERSIBLE BLADE AND WOOD RETAINING FERRULE Filed May 13,

I I I June '12, 11923.

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June 12, 1923.

E. G. M CAULEY PROPELLER REVERSIBLE BLADE AND WOOD RETAINING FERRULE Filed May 13. 1922 2 Sheets-Sheet 2 c/ r 1 v a 3 woe wto p 1 777655 14/ "601/269 anew,

-ber 491,973.

Patented date 112, 1923 UNTTED STATES ERNEST e. MQOAULEY, or Darren, onto. 1

PROPELLER REVERSIBLE BLADE AND WOOD -RETAINING FE RRULE.

Application filed May 13,

To all whom it may concern 3e it known that I, ERNEST G; MoCAULnr, a citizen of the United States, residing at Dayton, in thecounty of Montgomery and State of Ohio, have invented certain new and useful Improvements in Propeller Reversible Blades and VVood-Retaining Ferrules, of which the following is a specification. I

This invention relates in general to reversible propellers and more specifically to an improved means for mounting any propeller blade within a detachable ferrule.

This invention relates to an improved modification of my invention as disclosed in my copending application Serial Number 491,973, relating to propellers for aircraft, and filed Aug. 13, 1921.

It is the purpose of this invention to provide the necessary and novel means for mounting a wooden propeller blade, in place thereof, within a detachable ferrule, the op-' eration and the provision of bearing members in the construction of the apparatus being practically identical with that described in the abo-veco-pending application, and also my former application, Serial Num- To this end it is proposed to retain a wooden propeller blade by means of a suitable screw-threaded expanding ring bolts and nuts. \Vith the foregoing and other objects in view, the invention resides in the comb-inaion of parts and details of construction hereinafter described and claimed, the specific embodiment of my device being illustrated in the accompanying drawings, in which:

Figure 1 is a longitudinal section through the reversible propeller assembly.

Figure 2 is a. longitudinalsectio-n through the inner portion oi. t h propeller blade showing a connterbored portion in the inner end thereof to receive an expanding ring.

Figure 3 is a longitudinal section through a portion of th propeller blade showing the manner in which the expanding ring is mounted within its ferrule. V

Figure 1 is an end view of the inner end of the propeller blade showing counterbored portions to receive an expanding ring and allow for expansion of said bladef Figure 5 is a cross section through the ferrule, blade and expanding ring showing set screws to retain expanding ring concentric in ferrule and to absorb the driving 1922. Serial N0. 560,752.

force through the set screws instead of through the wood.

Figure 6 is a longitudinal view of propeller showing adjustable operating mean and connections of these parts. s Referring more particularly to the drawings, Figure 1 illustrates an adjustable and yariable pitch and reversible propeller, having a hub wit-hintegral shaft spindles and detachable ferrules provided with bearing members intermediate the ferrules and spindles practically identical with the construction and manner and means of operation described in the aforementioned application.

However, in the present invention, wooden e details of construction in the mounting of a wooden blade are proposed.

A counterbored concentric circular groove 5' is formed in the inner end of the wooden pro ellerblade 1 as shown in Figures 2 and 1. his groove 5 is for the purpose of receiving an expanding ring 5 for which the groove 5' acts as a guide in inserting the expanding ring 5. The object in, inserting the expanding ring 5 is to expand and compress the portion, 7 ot the wooden propeller blade su rounding said expanding ring, in order to etain samewithin the ferrule 1, and to allow for this expansion transverse saw-cuts or slots 14 are arranged in the inner end of the propeller blade and extend to practically the same depth as the guiding groove 5.

The expanding ring 5 is provided with an inturned flange 6, thus making a suitable seat for the radial bearing comprising races 9 and bearing members 10. The expanding ring 5 may 'be devoid of threads with its outer tapered surfaces smooth, as with this type of expanding ring it is only necessary to press the expanding ring straight into the counterbored portion of blade in the groove 5 to position it in ferrule 4. The preferred embodiment of the expanding'ring 5 as shown in F igure 3 is provided with an unthreaded portion at the small end, the remainder of the expanding ring having threads of gradually increasing depth, terminating with full threads at the large end.

olts 2 and 3 and nuts 2 are arranged in diametrically opposite relation to each other and ,at an angle of approximately -forty-five degrees with the grain of the proppller blades are used and certain changes in t Wood. Irregularity in the grain of the wood causes the knif edge to buckle and curl and thus gouge the wood, weakening and shearing tie texture thereof and lessening the tightness of the engagement of the wood with the wedge and consequently the wood with its retaining ferrule, thereby decreasing the efiiciency of the wedge in the performance of the function for which it is intended.

These difliculties are overcome in the present invention by counterbor'ng a concentric circular groove near the periphery of the inner end of the wooden propeller blade, the groove being of a sufficient width to receive only the blunt smaller end of the expanding ring and of a suitable depth to receive the entire expanding ring when forced or screwed thereinto. In allowing for expansion, transverse saw-cuts or slots extending from the groove to the periphery of-the blade, allowthe wood to expand evenly without destroying the texture thereof by the action of the expanding ring. The expanding ring may be devoid of screw threads. However, it is considered advantageous to have the expanding ring provided with screw threads in accordance with the illustration in Figure 3. In this case,-the expanding ring may be removed and the ferrule used again in case ofa breakage of the propeller blade. This is impossible in case of a knife-edged wedge as the latter is so mutilated by the action of the driving of it into the blade that it is unfit for use when removed. The provision of a screwthreaded expanding ring insures a tight engagement of the expanding ring with the wooden propeller and causes the expanding ring to be drawn into tighter engagement therewith, by the centrifugal force of the revolving blade, and also enables the expanding ring to be more easily removed, when desired, by means of spanner wrenches, or the like. Also when a screwthreaded expanding ring is used, suitable bolts 2 and 3 and nuts 2' allows the ferrule to be more readily taken off the wood blade.

Referring to Figure 5, which is a cross section along the line 5-5, a plurality of set screws 8 are located at intervals around the ferrule 4 and are provided to screw into the ferrule against the expanding ring 5 for the purposes of relieving the driving force of the hub concentrated to the ferrule and blade through the wood that is compressed between the expanding ring and ferrule,

which if not relieved from this stress might cause the wood to compress further and allow the expanding ring to become loose and.

eccentric with the center of the ferrule and blade.

Referring to lfigure 1, a propeller hub 16 having a tapered bore and mountedon the tapered end of an engine shaft is provided with opposed integral shaft spindles 17.

Blade 1 after being pressed into ferrule 4 and located by expanding ring 5 and bolts 2and 3, is mounted as a whole on shaft spindle 17. A blade aligning bearing 18 is pressed into the radial bearing seat of the expanding ring and intermediate with the shaft spindle. This with aligning bearing 12 provides means for rotatably mounting the blades on the hub member. An internal detachable thrust collar 11 provided with an inturned flange 11 is. screwed into the ferrule 4 and provides a suitable seat for the radial aligning bearing 12, and is locked to ferrule 4 by sea-t screws 15; placed at intervals around the ferrule. This thrust collar also serves to retain the blade andrelation to the shaft spindle 17 and also an equal distribution of load on the thrust bearing due to the centrifugal force of the blade. A smaller' thrust collar 21 is screwed on shaft spindle 17 and made to abut against thrust bearing race 20. After proper adjustment and alignment are made of these various parts by screwing and tightening the thrust collar'21, it is then locked in position by a slotted flange plate 22 made to bend over on the outer edge of same and lock nut 23. 'R-eferring to Figure 6 an operating ring 24 is adj ustably fitted around the ferrule by means of corresponding tapped holes 25 in operating ring 24 and the drilled holes 26 in the ferrule 4 to be engaged by the screw dowel27 safetied by wire 28. In order to further increase or de crease the pitch of the propeller, it is only necessary to remove the screw dowels 27 and rotate the ring 24 to engage another series of holes and again secure same in position by means of the dowels 27. The operating ring 24 being provided with a series of equally spaced tapped holes, to register with a series of drilled holes in ferrule suitably spaced to provide proper adjustment toallow either an increased or a decreased pitch blade setting. An offset lug 28 is made in-: te'gral with the operating ring 24 and pro- I nut 34 and safetied by lock wire 35.

with a radial thrust bearing 33 which is lookmounted thereon and held iniplace by a Antifriction balls 36 between the bearing races 33 and 37 allow the sliding yoke to rotate with the propeller, while an outer shifting control plate 38 and lock ring 39 engages the bearing race 37 which is non-rotating and being held so by a suitable propeller.co ntrol mechanism (not shown) adapted to engage threaded boss extensions 40 for the purpose of shifting the sliding yoke 31' forward or backward along the shaft hub 16 to effect the changing of the pitch of the propeller. Locking ring 39 is made with an enlarged diameter over thebearing race 37 leaving an opening 41 between the bearing race and the locking ring. This is.to facilitate in the adjustment of the locking ring 39 and shifting control plate 38 with the sliding yoke 31 and suitable propeller control mechanism (notshown),

Stop ring 42 is secured by screws 43 to the outer end of the sliding yoke 31 in order to provide a limiting stop means against said hub 16 at points 44 from increasing the pitch of the propeller blades beyond a determined' position.

A hub retaining nut 45 is provided to screw on the end of the engine shaft against the shoulder 46 of the hub to wedge the hub onto the engine shaft and held in place by a lock nut 47 screwed into the extension 48 of the hub 16.

Since it has been clearly shownthat the operating rings are adjustable, a greater range of the pitch of the propeller in favor of increasing the pitch can be obtained to allow the propeller to function properly when used in connection with an engine equipped with a supercharger, since a supercharger has the effect of maintaining what might be considered a constant horse power at the high altitudes it becomes necessary to increase the pitch of the propeller considerably over what is termed a normal or fixed pitch propeller in order to absorb the horse power given by an engine equipped with a supercharger. While in designing an adjustable pitch propeller of the type now being described the angular movement of the blades is limited to the length of the movement forwardlor backward of the sliding yoke along the hub. It is for this purpose that by adjusting the operating ring around on the ferrule while the sliding yoke is held stationary, considerably more increase or decrease pitch of the propeller may be obtained in the direction desired when properly adjusted'and positioned by screw dowels.

Having thus described my invention, I

claim: I

1. In a reversible propeller having a plurality of blades and ferrules, means for retaining each of said blades within its ferrule, said means comprising a screw-threaded expanding ring having a blunt edge adapted to engage a counterbored concentric circular groove in the base of said blade, said blade base being further provided with transverse slots for the purpose of insuring evenly distributed expansion of the blade base caused by the expanding actidn of the applied expanding ring.

2. In a reversible propeller, a propeller blade, a hub, a ferrule mounted on said hub, the base of said blade being provided with a counterbored concentric circular groove and a plurality of transverse slots, a blunt tapered screw-threaded expanding ring adapted to be screwed into said circular groove of lesser diameter for the purpose of expanding and compressing-the material of said blade against said ferrule, and rigidly securing said blade within said ferrule, said blade and ferrule further provided with bolts extending. therethrough and at an angle of 90 to each other and at an angle of 45 with the grain of the blade material.

3. A device for retaining a propeller blade within a ferrule, said device comprising a ferrule tapering from one end to a medial point, the inner base of said blade being provided with a counte'rbored concentric circular groove to receive an annular bluntedged screw-threaded expanding means. screwed into said circular groove to expand said blade to compressively fill the tapering portion of said ferrule, transverse boltsextending through said ferrule and said blade, said inner end of said blade being further provided with transverse slots to insure an evenly distributed expansionof said wood, or the like, by the action of said expanding means. I

4. In a reversible propeller having a plurality of blades and ferrules, means for retaining each of said blades within its ferrule, said means comprising an expanding ring member having a blunt edge adapted to engage a counterbored concentric circular groove. in the base of said blade, said blade base being further provided with transverse slots for the purpose of insuring evenly distributed expansion of the blade caused by the expanding action of the applied expand-- lng ring. said expanding ring being provided with an inturned flange at its smaller end to engage with and provide a seat for a radial bearing member, said ferrule being screwthreaded to receive an internal detachable threaded thrust collar provided with an inturned flange to engage with and provide a seat for a radial bearing member.

5. In a propeller, the combination with a iii] blade thereof, means for retaining said blade Within a ferrule,-said ferrule having an internal threaded portion to receive a detachable thrust collar, said thrust collar being provided with an inturned flange whose outer surface is suitably formed to abut against a thrust bearing to provide an alignment and even distribution of load between said thrust collar and said thrust bearing.

6. In a propeller, the combinationwith a blade thereof, of a ferrule having a tapered boreat one end and an expanding ring having a tapered threaded outer surface, said tapered threaded surface being adapted to be screwed into the counterbored end of said blade, and to bend and compress the material of said blade against the tapered surface of said ferrule and also into the threaded portion of said expanding ring, thereby forming means of rigidlyretaining said expanding ring longitudinally in said ferrule against the centrifugal force of the blades. 7. In a propeller, the combination with a blade thereof having a counterbored portion, of a ferrule, and an expanding ring adapted to be inserted in said counterbored portion for bending and compressing the material of the propeller blade against said ferrule, means for retaining said expanding ring concentric with said ferrule and absorbing the rotat ng force exerted on said ferrule by means consisting of set screws placed at intervals around and screwed into said ferrule and blade and against said expanding ring.

8. For use in an aircraft having an internal combustion engine'provided with a rotary shaft, a reversible propeller rigidly mounted on said shaft, said propeller having a hub with shaft spindles integral therewith, cylindrical ferrules rotatably mounted on said shaft spindles, a propeller blade havmg a counterbored portion, a screw-threaded expanding ring adapted to be screwed :into said counterbored portion for tlre purpose of compressing the blade material against said ferrule, and bolts extending through said blade and ferrules at points 1oeated beyond said counterbored portion, an adjustable operating ring provided with a slotted aperture for receiving operating pins, said operating rings being mounted on said ferrules,a cylindrical sliding-yoke rotating with and slidable longitudinally on said hub, said yoke having apertures to provide mountings for said operating pins, and ad justable shifting ring and a non-rotating threaded locking ring engaging and'mounted on an anti-friction bearing and sliding spindles, self-aligning anti-friction bearingsbet-ween said ferrules and said shaft spindles, a blade having a counterbored portion, a screw-threaded expanding ring adapted to be screwed in said co unterbored portion for bending and compressing the material in said blade between said expanding ring and ferrule, detachable bolts extending through said blades and ferrules, adjustable operating rings mounted on said ferrule, detachable operating pins, a cylindrical sliding yoke provided with pitch limiting devices. a yoke shifting ring adjustable with relation to the anti-friction bearing on said sliding yoke and propeller control mechanism, and a radial thrust bearing intermediate said sliding yoke'and said yoke shifting ring.

In testimon' whereof I afiix my signature.

I lRNEST G. MQCAULEY. 

